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Full text of "The Morphology And Evolution Of The Apes And Man"

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THE MUSCULAB SYSTEM                 181
vertebrae. The superior oblique part runs from the third, fourth and fifth cervical vertebrae to the anterior arch of the atlas; and the inferior oblique part connects the first four thoracic vertebrae to the fifth and sixth cervical vertebrae. The rectus capitis anticus major runs from the third, fourth, fifth and sixth cervical vertebrae to the basi-occiput. It may receive a slip from the scalenus anticus. The rectus capitis anticus minor is as in Man. In the Gorilla, according to Sommer (491), these muscles are as in Man. Kohlbriigge (199) describes an arrangement of the prevertebral muscles in the Gibbon which corresponds in general to the description of the Chimpanzee given above, but he does not divide the longus colli into three parts.
MUSCLES OP THE ARM.
The pectoralis major in the Chimpanzee consists of clavicular, costo-sternal and abdominal parts. The clavicular part arises from the inner half of the front of the clavicle; and it may derive fibres from the tendon of the sterno-mastoid. It is quite continuous with the costo-sternal part, no groove intervening as in the other Apes and Man. It may be fused with the deltoid, or there may be a delto-pectoral triangle containing the thoracic axis vessels and the external anterior thoracic nerve, but no cephalic vein nor lymph glands. The costo-sternal part arises from the sternum and first six costal cartilages, and it is fused with the external oblique muscle. It receives the abdominal part of the muscle. The insertion into the pectoral crest, capsule of the shoulder-joint and deep fascia of the arm is musculo-aponeurotic. The abdominal part is not specialized to form a separate